Weight Loss and AHI change

[firehawk12]

Ah, so people typically have problems exhaling and EPR is mostly a comfort feature then?

[jgjones1972]

As to whether or not this causes an arousal from sleep, well, that's the million dollar question. In a sleep study they'd know because they are monitoring your brain activity, but at home with a CPAP machine there's no way to tell if an apnea or a hypopnea caused an arousal.

If you already have a smart phone (iPhone or Android) you can get a ZEO for about $65 and monitor your brain activity - sleep/wake and sleep stages. It'll cost more if you don't have a smart phone and need the bed side unit. You can compare your ZEO chart with your charts from Sleepy Head, ResScan etc. and also with the Oximeter chart. The only problem is that the ZEO brain wave sensor goes on your forehead, which would cause problems if your mask has a forehead support.

[PaulaO2]

Ah, so people typically have problems exhaling and EPR is mostly a comfort feature then?

A lot of people do (have problems exhaling) in the beginning, especially at higher pressures. But after a while, most don't have any issues because their body and brain have adjusted..

EPR is a comfort feature but some people do better without it and some do better with it. As in better sleep and better numbers. I did a brief experiment with my Escape with turning the EPR off. For three days I had ear pressure but only for a short bit after putting the mask on each night. But after the 3 days, I didn't notice any difference. I decided, though, to put it back on 2 because I feel it helps me fall asleep faster. I don't notice my breathing as much during that time.

[firehawk12]

Ah, so people typically have problems exhaling and EPR is mostly a comfort feature then?

A lot of people do (have problems exhaling) in the beginning, especially at higher pressures. But after a while, most don't have any issues because their body and brain have adjusted..

EPR is a comfort feature but some people do better without it and some do better with it. As in better sleep and better numbers. I did a brief experiment with my Escape with turning the EPR off. For three days I had ear pressure but only for a short bit after putting the mask on each night. But after the 3 days, I didn't notice any difference. I decided, though, to put it back on 2 because I feel it helps me fall asleep faster. I don't notice my breathing as much during that time.

Ah, that makes sense. I've been on CPAP for a while now, so I don't really have any problems. When I got the S8, it seems like it was just set to 3 by default and I never noticed it.

[archangle]

It would seem that EPR would be simply a comfort feature. Some people find it makes their apnea numbers better or worse. I haven't heard really good explanations, but the human respiratory and nervous systems are complicated with lots of feedback.

My recommendation is to experiment with it.

[SleepingBetterNow]

According to a doctor I used to see, if CPAP pressure is too high, it prevents CO2 from building up in the blood, and that's what triggers the brain to send the signal to breathe. In other words, pressure that's too high for your OSA could trigger Central Apnea. I suppose it's possible that losing weight meant that you needed a lower pressure, or even that you no longer needed CPAP. This is just a guess, of course.

[Sleepster]

According to a doctor I used to see, if CPAP pressure is too high, it prevents CO2 from building up in the blood, and that's what triggers the brain to send the signal to breathe. In other words, pressure that's too high for your OSA could trigger Central Apnea. I suppose it's possible that losing weight meant that you needed a lower pressure, or even that you no longer needed CPAP. This is just a guess, of course.

That's what I thought, too. But if it were true the CA index would be elevated. And in this case it's the hypopnea index that's elevated. Moreover, it's a one day anomaly. You can't draw conclusions from one day of data.

[zonk]

According to a doctor I used to see, if CPAP pressure is too high, it prevents CO2 from building up in the blood, and that's what triggers the brain to send the signal to breathe. In other words, pressure that's too high for your OSA could trigger Central Apnea. I suppose it's possible that losing weight meant that you needed a lower pressure, or even that you no longer needed CPAP. This is just a guess, of course.

That's what I thought, too. But if it were true the CA index would be elevated. And in this case it's the hypopnea index that's elevated. Moreover, it's a one day anomaly. You can't draw conclusions from one day of data.

I've an S8 Autoset which occasionally use when away from home but decided not to use any more as not felt as rested as with the S9

my HI is always high on the S8 and hardly ever get mentioned on the S9
the S9 Autoset increase pressure in response to snore and flow limitation and apnea but not if central apnea detected

[the OP uses an S8 Elite (fixed pressure machine) the S8 don,t detect central apnea and don,t scored it either]

you can notice here (see graph) that CSA can occur at lower pressure too http://www.apneaboard.com/forums/Thread-...ults--2753

keep in mind that the machine have no way of knowing whether you,re asleep or not. in sleep lab setting, awake events are discarded for true AHI value. agree with Sleepster that "You can't draw conclusions from one day of data", its the trend over period of time that matter most

[Sleepster]

my HI is always high on the S8 and hardly ever get mentioned on the S9

I've seen other reports from folks too that the S9 measures differently than the S8.

[the OP uses an S8 Elite (fixed pressure machine) the S8 don,t detect central apnea and don,t scored it either]

I don't see how that's possible. Likely the S8 can't distinguish between a central apnea (CA) and an obstructive apnea (OA) so it simply counts them both as apneas.

Since the OP's S8 is not reporting a lot of apneas (compared to hypopneas) we can conclude that he's not experiencing a lot of CA's (compared to hypopneas).

[zonk]

I suppose it's possible that losing weight meant that you needed a lower pressure, or even that you no longer needed CPAP.

you need a sleep study to be sure